While Thor has proven himself to be an incredibly powerful being on a cosmic scale within the Marvel Universe, he originally had a power that made him an even greater threat to his enemies–one that Doctor Strange regularly utilizes in the MCU.
In the Marvel Cinematic Universe film Doctor Strange, Stephen Strange learns the ways of the mystic arts after his hands are crushed in a car accident, rendering him unable to continue his career as a surgeon. While he initially only wanted to use magic to heal his body, he proved to be incredibly gifted in the ways of magic and later became the Sorcerer Supreme, equipped with the power to manipulate the mystic arts and even reach into other dimensions–including a pocket space that acts simply as a reflection of the physical world and is void of indigenous life known as the Mirror Dimension. In Doctor Strange, Avengers: Infinity War, and Spider-Man: No Way Home, Doctor Strange utilizes the Mirror Dimension as a way to combat his enemies in a safe space that wouldn’t impact nearby civilians.
In Avengers #16 by Stan Lee, Jack Kirby, and Dick Ayers, the Avengers are battling the villainous group known as the Masters of Evil on the busy streets of New York City. While the Masters of Evil don’t care about innocent bystanders getting injured or even killed as a result of their battle, the Avengers immediately work to mitigate the damage and make the protection of New York’s residents their top priority. In that effort, Thor spins Mjolnir rapidly and opens a rift in space to another dimension, one that was completely void of life. Thor effectively transports the Avengers and the Masters of Evil to this alternate world where the heroes quickly defeat their villains as they didn’t have to fear for the safety of innocents.
Just as Doctor Strange can transport himself and his enemies to the Mirror Dimension, Thor originally had the power to do basically the same thing with the Asgardian magic he had access to through Mjolnir. Not only do both heroes have access to a dimension where they can safely fight their enemies, but both dimensions give the heroes a huge advantage over their opponents as well. Doctor Strange has complete control over the Mirror Dimension as a magic user, and similarly, the world Thor has access to grants the Avengers an advantage over the Masters of Evil as well. Thor’s dimension reverses any attack one tries to use against another onto themselves, meaning that when the Masters of Evil tried to use their powers against the Avengers, they immediately incapacitated themselves–allowing the Avengers to claim a quick and painless victory with no civilian casualties.
While the Doctor Strange’s Mirror Dimension and the world Thor transported the Masters of Evil to aren’t exactly the same, both maneuvers achieve exactly the same purpose in nearly identical ways–proving that Thor originally had Doctor Strange’s greatest MCU spell.
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